Plus, there is the human nature aspect. We are more likely to comment on remarkable behavior. If every FTer posted "I went through ABC today and nothing significant happened" it wouldn't make for very good reading. Since there are relatively few ways that a TSA screener can go above and beyond expectations in a good way, we are more likely to complain than compliment.

Policy issues aside, I have never had an issue with a front-line TSA person.